Anthony Fauci said recently that he is "not convinced" COVID-19 developed naturally and called for further investigation into the virus's origins after the lab-leak theory had been dismissed by many as a right-wing conspiracy theory for months.

At an event earlier this month, PolitiFact's Katie Sanders noted that there is still "a lot of cloudiness around the origins of COVID-19" and asked Fauci if he is "still confident that it developed naturally," according to footage of the event which was resurfaced by Fox News on Sunday.

“No actually,” Fauci said at the "United Facts of America: A Festival of Fact-Checking" event.

"I am not convinced about that," he added. "I think we should continue to investigate what went on in China until we continue to find out to the best of our ability what happened."

He continued: “Certainly, the people who investigated it say it likely was the emergence from an animal reservoir that then infected individuals, but it could have been something else, and we need to find that out. So, you know, that's the reason why I said I'm perfectly in favor of any investigation that looks into the origin of the virus."

The comments mark a shift from Fauci’s earlier position: In May 2020, the National Institute of Allergy and Infectious Diseases (NIAID) director largely dismissed the theory that the novel coronavirus could have leaked from a lab.

“If you look at the evolution of the virus in bats and what's out there now, [the scientific evidence] is very, very strongly leaning toward this could not have been artificially or deliberately manipulated,” he told National Geographic at the time.

“Everything about the stepwise evolution over time strongly indicates that [this virus] evolved in nature and then jumped species,” he added, telling the magazine that based on the scientific evidence, he did not entertain the lab leak theory.

The newly unearthed footage of the fact-checking event comes after Fauci did not explicitly rule out the possibility that COVID-19 "occurred by serial passage in a laboratory” during an exchange with Senator Rand Paul (R., Ky.) during a Senate hearing on Tuesday.

“I do not have any accounting of what the Chinese may have done, and I’m fully in favor of any further investigation of what went on in China,” Fauci said. “However, I will repeat again, the NIH and NIAID categorically has not funded gain of function research to be conducted in the Wuhan Institute of Virology.”

Paul blasted Fauci during the hearing for continuing to defend gain-of-function research — which involves making viruses more infectious and/or deadly — despite the possibility that the novel coronavirus leaked from a laboratory that was performing such research in Wuhan, China.

Paul asked Fauci if he still supports National Institutes of Health funding for the Wuhan Institute of Virology, where scientists performed gain-of-function research on bat coronaviruses. The EcoHealth Alliance diverted $600,000 in grants from the NIH to the WIV in the form of sub-grants from 2014 through 2019, for the purpose of studying bat coronaviruses.

"For years, Dr. Ralph Baric, a virologist in the U.S., has been collaborating with Dr. Shi Zhengli from the Wuhan Virology Institute, sharing his discoveries about how to create superviruses," Paul said. "This gain-of-function research has been funded by the NIH. . . . Dr. Fauci, do you still support funding of the NIH lab in Wuhan?"

"Senator Paul, with all due respect, you are entirely and completely incorrect," Fauci said. "[The] NIH has not ever and does not now fund gain-of-function research in the Wuhan Institute of Virology."

However, the U.S. government has reportedly assessed that the WIV was conducting gain-of-function research in some form, according to a Politico in March. Jamie Metzl, an expert on gene editing for the World Health Organization, has also said that the WIV performed gain-of-function research.

Yet while the World Health Organization (WHO) initially declared the lab-leak theory “extremely unlikely,” WHO chief, Dr. Tedros Adhanom Ghebreyesus has said the research team’s probe into whether the virus may have escaped following a laboratory incident was not “extensive enough” and requires more investigation.

White House Press Secretary Jen Psaki said this week the Biden administration has expressed both publicly and privately that the Chinese government was “not transparent from the beginning.”